content: /*
   * Copyright 2017 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.reactive4javaflow.impl;
  
  import hu.akarnokd.reactive4javaflow.FolyamPlugins;
  import hu.akarnokd.reactive4javaflow.fused.ConditionalSubscriber;
  
  import java.lang.invoke.VarHandle;
  import java.util.concurrent.Flow;
  
  public final class HalfSerializer {
  
      private HalfSerializer() {
          throw new IllegalStateException("No instances!");
      }
  
      public static <T> void onNext(Flow.Subscriber<T> actual, Object target, VarHandle WIP, VarHandle ERRORS, T item) {
          if ((int)WIP.getAcquire(target) == 0 && WIP.compareAndSet(target, 0, 1)) {
              actual.onNext(item);
              if (!WIP.compareAndSet(target, 1, 0)) {
                  Throwable ex = ExceptionHelper.terminate(target, ERRORS);
                  if (ex == null) {
                      actual.onComplete();
                  } else {
                      actual.onError(ex);
                  }
              }
          }
      }
      public static <T> boolean tryOnNext(ConditionalSubscriber<T> actual, Object target, VarHandle WIP, VarHandle ERRORS, T item) {
          if ((int)WIP.getAcquire(target) == 0 && WIP.compareAndSet(target, 0, 1)) {
              boolean b = actual.tryOnNext(item);
              if (!WIP.compareAndSet(target, 1, 0)) {
                  Throwable ex = ExceptionHelper.terminate(target, ERRORS);
                  if (ex == null) {
                      actual.onComplete();
                  } else {
                      actual.onError(ex);
                  }
                  return false;
              }
              return b;
          }
          return false;
      }
  
      public static void onError(Flow.Subscriber<?> actual, Object target, VarHandle WIP, VarHandle ERRORS, Throwable t) {
          if (ExceptionHelper.addThrowable(target, ERRORS, t)) {
              if ((int) WIP.getAndAdd(target, 1) == 0) {
                  Throwable ex = ExceptionHelper.terminate(target, ERRORS);
                  actual.onError(ex);
                  return;
              }
          }
          FolyamPlugins.onError(t);
      }
  
      public static void onComplete(Flow.Subscriber<?> actual, Object target, VarHandle WIP, VarHandle ERRORS) {
          if ((int) WIP.getAndAdd(target, 1) == 0) {
              Throwable ex = ExceptionHelper.terminate(target, ERRORS);
              if (ex == null) {
                  actual.onComplete();
              } else {
                  actual.onError(ex);
              }
          }
      }
  }
  